JPH0745971Y2 - Electrostrictive effect element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an electrostrictive effect element, and more particularly to an electrode structure of a laminated electrostrictive effect element utilizing a vertical effect.

[Prior Art] FIG. 4 (a) is a conventional perspective view of an electrostrictive effect element of this type,
FIG. 4 (b) is a vertical sectional view thereof.

A plurality of electrostrictive materials 1 are provided above and below the terminal connecting portion 3 made of the electrostrictive material 1.
And the internal electrodes 2 are alternately laminated to form a laminated body. The electrostrictive material 1 is made of a ceramic such as lead zirconate titanate having a composite perovskite structure, and the internal electrode 2 is made of a silver-palladium alloy or the like. In addition, on the side surface of the electrostrictive effect element shown in the drawing, the end surfaces of the internal electrodes 2 are coated and insulated by the insulating substances 4a and 4b every other layer, and the coating is provided every other layer on both side surfaces of the electrostrictive effect element. It is provided to be staggered. External electrodes 5a and 5b are attached and disposed on the coatings of the insulating materials 4a and 4b to electrically connect the internal electrodes 2 of the electrostrictive effect element every other layer. In addition, the insulating material 4a, 4
Solder resists 8a and 8b are applied on b and the external electrodes 5a and 5b. Further, the lead wires 6a, 5b are connected to the external electrodes 5a, 5b on the terminal connecting portion 3 located at the center of the electrostrictive effect element.
6b is electrically connected by solder 7. Therefore, when a predetermined voltage is applied between the lead wires 6a and 6b, the voltage is applied to all the internal electrodes 2 through the external electrodes 5a and 5b, and the entire element is distorted in the X and Y directions indicated by the arrows in the figure due to the vertical effect. .

[Problems to be Solved by the Invention] The conventional electrostrictive effect element described above has the following drawbacks.

(1) Solder resist is applied to the external electrodes to prevent the solder from adhering to the insulating material, which causes stress on the adhesive surface of the solder resist when the electrostrictive effect element is driven. Stress is applied to the underlying insulating material, causing dielectric breakdown.

(2) For this reason, if the terminal connection portion of the soldering portion is made thick, the total length of the electrostrictive effect element becomes large, and the product becomes large.

(3) Since the soldering area is determined by the width of the external electrode along the entire length of the side surface, the soldering area cannot be made large, and the soldering work is difficult to perform and the work efficiency is reduced.

[Means for Solving the Problems] The electrostrictive effect element of the present invention comprises a terminal connecting portion in which a plurality of electrostrictive materials are laminated, and an electrostrictive portion in which a plurality of electrostrictive materials and internal electrodes are alternately laminated. A laminate having, and an insulating material is alternately applied on the pair of side surfaces to one end surface of the internal electrode exposed on the pair of side surfaces facing each other of the laminated body, and the other of the internal electrodes to which the insulating material is not applied. The end portion is connected to an external electrode provided on each side surface, and in the electrostrictive effect element in which a lead wire is taken out from the external electrode on the terminal connection portion, the external electrode is on the electrostrictive material layer. The external electrodes are provided and a plurality of external electrodes are provided on the terminal connection portion in the lateral width direction and connected to the external electrode layers.

[Operation] Since the plurality of external electrodes arranged along the entire length of the side surface are connected to the electrode surface arranged in the width direction of the side surface at the terminal connection portion, the solder does not adhere to the insulating material and heat stress The insulating material is no longer destroyed. By using a plurality of external electrodes arranged along the entire length of the side surface, the width of each external electrode can be reduced, and the terminal connection portion can be reduced accordingly. Since no solder resist is used, the number of work steps can be reduced.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.

1 (a) is a perspective view of an electrostrictive effect element showing a first embodiment of the present invention, FIG. 1 (b) is a vertical sectional view of FIG. 1 (a), and FIG. 3 (a) is a book. It is a pattern diagram of external electrodes 5a and 5b of an example. The same symbols as in FIG. 4 indicate the same members.

In the electrostrictive effect element of this embodiment, the external electrode layers 5a and 5b are H-shaped, and the central lead wires 6a and 6b are formed so as not to protrude from the terminal connecting portion 3.

Next, a method of manufacturing the electrostrictive effect element according to the present embodiment will be described.

First, prepare a calcined powder of ceramics such as lead titanate, disperse it in an organic solvent such as ethyl cellosolve together with a small amount of an organic binder such as polybutyral resin and a plasticizer such as dioctyl phthalate, and doctor sludge. Using a slip casting method, a fluid film was applied on a polyester film with a thickness of 100 μm to obtain a thickness of 7
The electrostrictive material 1 is formed by depositing in the shape of a green sheet of 0 μm. Next, a conductor paste such as a silver-valadium paste is applied on the green sheet by screen printing to form the internal electrodes 2. Then, the green sheet in the portion where the internal electrodes 2 are printed is cut into a predetermined size and peeled from the polyester film. A desired number of the green sheets are stacked and pressed from above and below by a hot press to form a laminated body in which the electrostrictive material 1 and the internal electrode 2 are alternately arranged. In addition, in the step of stacking the green sheets, dozens of green sheets on which the internal electrodes 2 are not formed are stacked so as to be located in the central portion of the stack to form the insulating terminal connecting portion 3 as a dummy layer. To do. next,
After the organic binder contained in this laminate is decomposed at high temperature and evaporated to be removed, the temperature is raised to 1120 ° C. at a heating rate of 5 ° C./min. Do. Next, when the laminated body after sintering is cut into a lattice shape, the end faces of the internal electrodes 2 are exposed. An insulating material 4a, such as glass, is deposited on one end surface of the inner electrode 2 by an electrophoretic method at every other end surface, and on the other side, the reverse of the internal electrode 2 not coated with the insulating material 4a. The insulating material 4b is applied to the end surface that faces the side. In order to make an electrical connection from the upper surfaces of the insulating substances 4a and 4b to the internal electrodes 2 on which the insulating substances 4a and 4b have not been deposited, an H-shaped structure as shown in FIG. A conductive paste such as a silver paste is screen-printed using a screen mask (not shown) over the entire length of the stack to form the external electrodes 5a and 5b. Next, the external electrode 5 on the terminal connecting portion 3 at the center of the laminated body
The lead wires 6a and 6b are connected to a and 5b with solder 7 to complete the electrostrictive effect element of this embodiment.

2 (a) is a perspective view of an electrostrictive effect element showing a second embodiment of the present invention, FIG. 2 (b) is a vertical sectional view of FIG. 2 (a),
FIG. 3B is a pattern diagram of the external electrodes 5a and 5b of this embodiment. The same symbols as in FIG. 4 indicate the same members.

In the electrostrictive effect element of this embodiment, the external electrodes 5a, 5b are U-shaped, and the lead wires 6a, 6b at the lower end are formed so as not to protrude from the terminal connecting portion 3.

Next, a method for manufacturing the electrostrictive effect element according to the present embodiment will be described.

In FIG. 2, a desired number of green sheets having the internal electrodes 2 printed thereon are stacked on the electrostrictive material 1 in the stacking step of the manufacturing method of the first embodiment, and the green sheet is stacked on top or bottom (first or second). In FIG. 2, several tens of green sheets on which the internal electrodes 2 are not formed are stacked in the lower example), and a green laminate is formed by pressure bonding from above and below by a hot press so that the terminal connecting portions 3 are formed. Then, the external electrodes 5a and 5b are formed by using the screen mask as shown in FIG. 3 (b) by the same method as in the first embodiment, and then the external electrodes 5a and 5b on the terminal connecting portion 3 under the laminated body are formed. The lead wires 6a and 6b are connected by the solder 7 to complete the electrostrictive effect element of this embodiment.

The electrostrictive effect element of this example has a rectangular cross section in the stacking direction, but it goes without saying that it may have a circular, ring, or polygonal cross section. Further, the number of external electrodes arranged on the electrostrictive material 1 may be three or more.

[Effects of the Invention] As described above, the present invention provides a plurality of external electrodes having external electrodes arranged along the entire length of the side surface, and external electrodes arranged in the lateral direction of the side surface connected to the external electrodes at the terminal connecting portions. The following effects can be obtained by constituting with electrodes.

(1) Since the electrode surface intersects with the external electrode arranged along the entire length of the side surface, the solder does not adhere to the insulating material, and the insulating material is not destroyed by thermal stress.

(2) Since it is not necessary to apply an insulating resin such as a solder resist, the number of work steps can be reduced.

(3) The electrode surface size of the terminal connecting portion can be expanded to the entire width of the side surface, which facilitates the soldering work and improves the work efficiency.

(4) By using a plurality of external electrodes arranged along the entire length of the side surface, the external electrode width of the terminal connecting portion can be reduced without changing the allowable current amount flowing into the element. Since the terminal connecting portion can be made smaller by this reduction, the product can be made smaller. Further, if the size remains the same, the amount of strain rate increases with respect to the entire length of the electrostrictive effect element, and the performance improves.

[Brief description of drawings]

1 (a) and 1 (b) are perspective views and longitudinal sectional views of an electrostrictive effect element showing a first embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are second and third embodiments of the present invention. FIG. 3 is a perspective view and a longitudinal sectional view of an electrostrictive effect element showing an embodiment, FIG. 3 is a pattern view of external electrodes 5a, 5b of the first and second embodiments, FIG. 4 (a),
(B) is a perspective view and a longitudinal sectional view of a conventional example of an electrostrictive effect element. 1 ... Electrostrictive material, 2 ... Internal electrode, 3 ... Terminal connection part, 4
a, 4b ... Insulating material, 5a, 5b ... External electrode, 6a, 6b ... Lead wire, 7 ... Solder, 8a, 8b ... Solder resist.

Claims (1)

[Scope of utility model registration request] 1. A laminate having an electrostrictive portion in which a plurality of electrostrictive materials and internal electrodes are alternately laminated, and a terminal connecting portion made of an electrostrictive material having a thickness larger than one of the electrostrictive materials; Insulating substances are alternately applied on the pair of side faces to one end face of the internal electrodes exposed on the pair of opposite side faces of the laminated body, and the other ends of the internal electrodes to which the insulating substance is not applied are One side surface of the pair of side surfaces is connected to a first external electrode provided so as to cross the insulating material, and the other side surface of the pair of side surfaces is provided so as to cross the insulating material. The first and second terminals connected to a second external electrode and located on the terminal connecting portion.
In the electrostrictive effect element in which the first and second lead wires are electrically connected to the external electrode, the third external electrode is adjacent to the first external electrode on the one side surface. A fourth external electrode is provided on the terminal connecting portion so as to traverse an insulating material and electrically connects the first external electrode and the third external electrode, and A first lead wire is connected to the fourth external electrode via a fixing means,
On the other side surface, a fifth external electrode is provided so as to be adjacent to the second external electrode so as to cross the insulating material, and the second external electrode and the fifth external electrode are electrically connected to each other. A sixth external electrode is provided on the terminal connecting portion so as to be electrically connected, and the second lead wire is connected to the sixth external electrode via a fixing means. Electrostrictive effect element.